For six months, the White House claimed that this scandal was nothing more than innuendo about Trump campaign collusion with Russia in meddling in the 2016 election. Innuendo for which no concrete evidence had been produced.

Yes, there were several meetings with Russian officials, some only belatedly disclosed. But that is circumstantial evidence at best. Meetings tell you nothing unless you know what happened in them. We didn't. Some of these were casual encounters in large groups like the famous July 2016 Kislyak-Sessions exchange of pleasantries at the Republican National Convention. Big deal.

I was puzzled. Lots of cover-up, but where was the crime? Not even a third-rate burglary. For six months, smoke without fire. Yes, President Trump himself was acting very defensively, as if he were hiding something. But no one ever produced the something.

My view was: Collusion? I just don't see it. But I'm open to empirical evidence. Show me.

The evidence is now shown. This is not hearsay, not fake news, not unsourced leaks. This is an email chain released by Donald Trump Jr. himself. A British go-between writes that there's a Russian government effort to help Trump Sr. win the election, and as part of that effort he proposes a meeting with a "Russian government attorney" possessing damaging information on Hillary Clinton. Moreover, the Kremlin is willing to share troves of incriminating documents from the Crown Prosecutor. (Error: Britain has a Crown Prosecutor. Russia has a State Prosecutor.)
Donald Jr. emails back. "I love it." Fatal words.

Once you've said "I'm in," it makes no difference that the meeting was a bust, that the intermediary brought no such goods. What matters is what Donald Jr. thought going into the meeting, as well as Jared Kushner and then-campaign manager Paul Manafort, who were copied on the correspondence, invited to the meeting, and attended.

"It was literally just a wasted 20 minutes, which was a shame," Donald Jr. told Sean Hannity. A shame? On the contrary, a stroke of luck. Had the lawyer real stuff to deliver, Donald Jr. and the others would be in far deeper legal trouble. It turned out to be incompetent collusion, amateur collusion, comically failed collusion. That does not erase the fact that three top Trump campaign officials were ready to play.

It may turn out that they did later collaborate more fruitfully. We don't know. But even if nothing else is found, the evidence is damning.

It's rather pathetic to hear Trump apologists protesting that it's no big deal because we Americans are always intervening in other people's elections, and they in ours. You don't have to go back to the '40s and '50s when the CIA intervened in France and Italy to keep the communists from coming to power. What about the Obama administration's blatant interference to try to defeat Benjamin Netanyahu in the latest Israeli election? One might even add the work of groups supported by the U.S. during Russian parliamentary elections -- the very origin of Vladimir Putin's deep animus toward Hillary Clinton, then secretary of state, whom he accuses of having orchestrated the opposition.

This defense is pathetic for two reasons. First, have the Trumpites not been telling us for six months that no collusion ever happened? And now they say: Sure it happened. So what? Everyone does it.

What's left of your credibility when you make such a casual about-face?

Second, no, not everyone does it. It's one thing to be open to opposition research dug up in Indiana. But not dirt from Russia, a hostile foreign power that has repeatedly invaded its neighbors (Georgia, Crimea, Eastern Ukraine), that buzzes our planes and ships in international waters, that opposes our every move and objective around the globe. Just last week the Kremlin killed additional U.N. sanctions we were looking to impose on North Korea for its ICBM test.

There is no statute against helping a foreign hostile power meddle in an American election. What Donald Jr. -- and Kushner and Manafort -- did may not be criminal. But it is not merely stupid. It is also deeply wrong, a fundamental violation of any code of civic honor.

I leave it to the lawyers to adjudicate the legalities of unconsummated collusion. But you don't need a lawyer to see that the Trump defense -- collusion as a desperate Democratic fiction designed to explain away a lost election -- is now officially dead.